CVE-2026-49136

Banana Slides 0.4.0 Path Traversal via generate_image() in ai_service.py

Published Jun 1, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Description

Banana Slides through 0.4.0, patched in commit e8bc490, contains a path traversal vulnerability in the generate_image() function within the AI service backend that allows unauthenticated attackers to read arbitrary image-format files outside the intended uploads directory by exploiting an incomplete path prefix check using os.path.startswith() without a trailing separator. Attackers can supply crafted markdown image references in user-controlled page descriptions that resolve to sibling directories whose names share the uploads folder prefix, bypassing the directory confinement check and causing the application to read files from unintended locations via PIL Image.open().

Analysis

Technical impact

A path traversal flaw in the generate_image() function of Banana Slides 0.4.0 lets attackers craft markdown image references that cause the application to read arbitrary image-format files outside the intended uploads directory. The flaw arises from an incomplete prefix check using os.path.startswith() without a trailing separator, enabling directory confinement bypass. As a result, unauthenticated attackers can read any accessible file that resides in a sibling directory whose name shares the uploads folder prefix, potentially exposing sensitive data.

Affected Systems

The vulnerability affects Anionex Banana Slides version 0.4.0. The patch is implemented in commit e8bc490, which is included in later releases.

Risk and Exploitability

The CVSS score of 8.7 classifies this exploit as high severity. No EPSS data is available, and the vulnerability is not listed in the CISA KEV catalog. Attackers only need to supply a crafted image reference within an unauthenticated user‑controlled page description; the backend then opens the target file with PIL Image.open(), making the attack straightforward and requiring no additional privileges.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Anionex

banana-slides

affected

Version	Status	Constraints
`0`	affected	≤ 0.4.0
`e8bc490ec8b4b657e07dc3ab4e94fbedcaade421`	unaffected	—

No data.

Vendor Product Versions

Anionex

Banana-slides

Version	Status	Scheme	Platform
`[0,0.4.0]`	affected	semver	—
`e8bc490ec8b4b657e07dc3ab4e94fbedcaade421`	unaffected	code_commit	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Update Banana Slides to the patched version that includes commit e8bc490 or later
Enforce strict path validation by ensuring the uploads directory name ends with a separator before checking with startswith
Restrict file reading to allowed image types and directories, using a whitelist approach and sanitizing markdown input

Generated by OpenCVE AI on June 1, 2026 at 21:23 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.417% probability within 30 days)

Exploitation poc

Automatable yes

Technical Impact partial

References

Link	Providers
https://github.com/Anionex/banana-slides/commit/e8bc490ec8b4b657e07dc3ab4e94fbedcaade421
https://github.com/Anionex/banana-slides/issues/429
https://github.com/Anionex/banana-slides/pull/430
https://www.vulncheck.com/advisories/banana-slides-path-traversal-via-generate-image-in-ai-service-py

History

Jun 3, 2026 2:30 AM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Anionex Anionex banana-slides
Vendors & Products		Anionex Anionex banana-slides

Jun 2, 2026 4:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Jun 1, 2026 8:30 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		Banana Slides through 0.4.0, patched in commit e8bc490, contains a path traversal vulnerability in the generate_image() function within the AI service backend that allows unauthenticated attackers to read arbitrary image-format files outside the intended uploads directory by exploiting an incomplete path prefix check using os.path.startswith() without a trailing separator. Attackers can supply crafted markdown image references in user-controlled page descriptions that resolve to sibling directories whose names share the uploads folder prefix, bypassing the directory confinement check and causing the application to read files from unintended locations via PIL Image.open().
Title		Banana Slides 0.4.0 Path Traversal via generate_image() in ai_service.py
Weaknesses		CWE-22
References		https://github.com/Anionex/banana-slides/commit/e8bc490ec8b4b657e07dc3ab4e94fbedcaade421 https://github.com/Anionex/banana-slides/issues/429 https://github.com/Anionex/banana-slides/pull/430 https://www.vulncheck.com/advisories/banana-slides-path-traversal-via-generate-image-in-ai-service-py
Metrics		cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}` cvssV4_0 `{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}`